Project Summary/Abstract This career development proposal is designed to provide Dr. Michael Pulia, an Emergency Medicine specialist at the University of Wisconsin School of Medicine and Public Health, with the training required for success as an independent, physician-scientist researching interventions to improve the care of infectious diseases in the emergency department (ED). Inappropriate use of antibiotics in healthcare settings is a global public health threat due to an association with increasing rates of antibiotic resistant bacterial infections. Additionally, antibiotic overuse poses a significant patient safety concern due to the risk of serious adverse drug events such as anaphylaxis and Clostridium difficile diarrhea. The ED increasingly functions as the de facto center of the healthcare system and antibiotics prescribed here have significant downstream effects in both inpatient and outpatient settings. The ED has also been identified as the clinical environment with the highest rates of inappropriate antibiotic use. For example, antibiotic use for common skin and soft tissue infections, such as abscesses and cellulitis, in the ED fails to adhere to best practice guidelines in up to 90% of cases. Unfortunately, there are significant gaps in knowledge regarding the barriers to and facilitators of appropriate antibiotic use in the ED. This lack of understanding is reflected by the absence of antibiotic stewardship interventions tailored for the ED. The overall objective of the proposed research is to develop an evidence- based intervention bundle that improves guideline adherent antibiotic use for ED patients with skin and soft tissue infections. Given the complex nature of this clinical dilemma, the research approach will be guided by an innovative conceptual framework which has demonstrated success in other healthcare safety and quality improvement initiatives, the Systems Engineering Initiative for Patient Safety (SEIPS). The SEIPS model is designed to systematically identify all elements of the healthcare system that impact care delivery and patient outcomes. To achieve the overall goal, a mixed methods approach will be applied to address the following specific aims:1) Identify high impact barriers and facilitators to guideline adherent antibiotic use for the treatment of skin and soft tissue infections in the ED; 2) Design an ED antibiotic stewardship intervention bundle targeted to high impact barriers and facilitators then refine it using input from expert key stakeholders; 3) Implement an antibiotic stewardship intervention bundle and measure its impact on guideline adherent antibiotic use for skin and soft tissue infections in an academic ED. As a junior faculty member at an institution with extensive infrastructure to support early stage investigators, Dr. Pulia is in an ideal environment to complete the proposed research and pursue advanced training. His career development plan includes both coursework and mentored training in the areas of human factors and healthcare systems engineering, qualitative methods, interventional health services, and leadership/change management. To ensure success, he has identified committed, expert mentors in these disciplines and secured protected time for this work.